Safety cut-off device for gas service



Jan. 25,1927. 1,615,776

- W. G. SLATER SAFETY CUT-OFF DEVICE FOR GAS SERVICE Filed Oct. 10, 1923 Patented Jan. 25, 1927.

UNETED STATES WALTER GAY SLATER, 0F DODGE CITY, KANSAS.

SAFETY CUT-OFF DEVICE FOR GAS QEBVICE.

Application filed Gctober 10, 1923.

My invention relates to gas valves, and especially to emergency control or cut oft valves intended to act in response to decrease in pressure to close the inlet, so that it can be reopened by hand only.

My invention has for its object the production of a valve of this type which when closed shall be proof against leakage, can be readily reset. when open will leave a clear straightaway passage from inlet to outlet ports, when closed will permit venting and release of pressure in the valve chainbcrs, and at all times will be under spring tension toward closing independently of its own weight. An additional object is to so design the structure that the valve proper, and its casing will be compact, while the controlling diaphragm can be large enough to operate with certainty on a low pressure of gas.

I attain these objects by making a straightaway casing with a taper plug, and inlet and outlet ports in alignment, the plug being raised and lowered in a taper seat by means of parts mounted above and entirely outide of the casing. These comprise a pair of expansion diaphragms secured together around their peripheries, the lower one open in the center and secured to the casing gas tight, and the plug carried by the upper one, its stem working through the central opening in the lower one into the casing. The stem is extended through the upper diaphragm gas tight to give a hand hold, and its movement is limited by an overlying guard or limiting stop curved down on both sides and secured to the casing. The diaphragms are preferably metal, and have sufiicient curvature and resilience to maintain a constant downward spring pressure 011 the plug stern. and plug, even when the latter is seated.

Details of construction will sulliciently appear from the specific description here inafter.

My invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a side view of my valve complete,

Fig. 2 is an end view of the same.

Fig. 3 is a cross section on the line of Fig. 2, and

Fig. 4 is a sectional view on the line of Fig. 2 with the valve and diaphragm in open position. and showing the plug and. trail in attendee,

Serial No. 667,764.

Referring to the drawings, my device is composed of three essential parts, viz, the valve unit proper, the operating diaphragm structure, and the guard or limiting stop for the latter. The first element is a unit having cast body 1, with straightaway gas passage through it when open, as shown in Fig. 4, from inlet 2 to outlet 3, and a vertical taper bore 4: closed at its lower end by cap 4, and at its upper end by' the diaphragm structure. In this taper bore a taper plug 9, which can be given a ground fit, works vertically, being hung from the said diaphragm structure. The plug is provided with vent passages 10, 11, 12, which when the plug is down and the valve closed, connect the spaces above and below it to the outlet port 3. The valve is shown closed in Fig. 3 and open in Fig. 4.

The second element or diaphragm structure is composed of an upper disc 6*. a lower disc 6 having a central opening 6 and a threaded collar 6 which is integrally secured. to the lower disc around said opening and screws onto the upper end of the valve casing or body 1. The two discs 6 and 6 are secured together around their periphcries. The plug 9 is hung from the upper disc 6 by means of a stem 9 passing through the opening 6 of the lower disc 6 and havin its upper end reduced to pass through the disc 6 and threaded to receive a clamping head or nut 8 on the outside of the same. All joints and connections of the diaphragm elements are gas tight, and all parts preterably of metal.

The third element is the guard or limiting stop 7, shown in side elevation in Fig. 2 and in section in the other figures, which are all sighted at right angles to Fig. 2. This guard and stop is essentially a metal loop secured at its ends '7 to lugs 1 on opposite sides of-the body 1, by any suitable means which will keep the loop vertical, without permitting it to turn, as for example by squared shoulders on the lugs 1*, and screws tapped therein. The upper part of the guard is curved to follow generally the contour of the upper diaphragm disc 6* when expanded as in Fig. 4, and is so proportioned and set that when the diaphragm is so expanded and the valve open, the nut 8 will lie against the lower face of the guard, as shown in Fig. 4. A

111 speed when pressifire is on. and 11V valve open as shown in Fig. a, the plug will be held up by the diaphragm disc 6. If the pressure drops below the low limit, the natural resilience ofthe diaphragm discs aided by the weight of the plug, causes the latter to drop into the closed position shown in Figs. 1, 2 and 8 closing the inlet 2, and connecting the spaces above and below the plug to the outlet 3 to vent the same, and avoid any possibility of compression in the seating of the plug. When the valve is closed it can only be reopened by raising the head on the top or" the upper disc manually, and thereby lifting the plug and opening the passa 'e.

What fclaim is:

1. A safety cut off device for gas lines comprising a valve casing having a central chamber or bore, a plug reciprocating therein to open and close the valve, inlet and outlet ports opening into said bore in alignment with each other below the lower end of the plug when in open position. and an expansible gas chamber composed of a pair of resilient discs, peripherally connected, the lower one centrally perforated and secured gas tight to the valve casing and the upper one secured to said plug through the central perforation in the other, said plug being provided with means to vent said gas chamher when in its closed position.

2. A safety cut of]? device for gas lines comprising a valve casing having a central chamber or bore, a plug reciprocating therein to open and close the valve, inlet and outlet ports opening into said bore in alignment with each other below the lower end of the plug when in open position, and an expansible gas chamber formed of two disks secured together around their edges, the lower one centrally perforated and secured gas tight to the valve casing and the upper one secured to said plug through the central perforation in the other, bleeding pziissages being provided within said plug connecting the spaces above and below the same to the outlet port to vent the same and avoid any compression therein.

In testimony whereof I hereunto allix my signature.

VALTER GAY SLATER. 

